灯盏乙素通过STAT3信号对激活的BV-2小胶质细胞M2型极化的影响

Effect of Scutellarin on M2-type polarization in activated BV-2 microglia via STAT3 signaling

目的探究灯盏乙素(Scutellarin)对脂多糖(Lipopolysaccharide,LPS)作用下M2型小胶质细胞极化的作用及信号转导和转录激活因子3(signal transducers and activators of transcription 3,STAT3)的调控机制。方法BV-2小胶质细胞分为对照组(Con组)、STAT3抑制剂α-氰基-(3,4-二羟基)-N-苄基霉素-烟酰胺组(AG490组)、LPS组、LPS+AG490组、LPS+灯盏乙素预处理组(LPS+S组)、LPS+S+AG490组,共6组。Western blot和免疫荧光染色检测STAT3、磷酸化STAT3(P-STAT3)和M2型小胶质细胞标记物白介素10(IL-10)的表达。结果Western blot结果显示,LPS组的P-STAT3、IL-10表达显著增强,与对照组差异显著(P<0.05);使用灯盏乙素干预后P-STAT3表达明显降低;IL-10表达显著增高;均与LPS组有显著差异(P<0.05)。AG490增强灯盏乙素的作用。此外,STAT3在各组的变化无统计学意义(P>0.05)。免疫荧光染色结果显示,灯盏乙素干预后可降低LPS激活的BV-2小胶质细胞P-STAT3的蛋白表达水平;增强IL-10蛋白表达。各组STAT3的蛋白水平无统计学意义。结论灯盏乙素通过抑制STAT3活化促进BV-2小胶质细胞向M2型极化,可能与灯盏乙素减轻神经炎症反应有关。

Objective To investigate the role of scutellarin on the polarization of M2 microglia under the action of lipopolysaccharide(LPS)and the regulation mechanism of signal transducers and activators of transcription 3(STAT3).Methods BV-2 microglia were divided into a control group(Con),a STAT3 inhibitorα-cyano-(3,4-dihydroxy)-N-benzylmycin-nicotinamide group(AG490),a LPS group(LPS),a LPS+AG490 group,a LPS+scutellarin pretreatment group(LPS+S),a LPS+S+AG490 group.The expression of STAT3,phosphorylated STAT3(P-STAT3)and the M2 microglia marker interleukin 10(IL-10)were detected by Western Blot and immunofluorescence staining.Results Western Blot results showed:the expression of P-STAT3 and IL-10 in the LPS group was significantly enhanced,compared with that in the control group(P<0.05);the expression of P-STAT3 was significantly reduced,the expression of IL-10 was obviously increased after pretreatment with scutellarin;both were significantly different from the LPS group(P<0.05).AG490enhanced the effect of scutellarin.In addition,there was no statistical difference s in STAT3 in each group(P>0.05).Immunofluorescence staining results showed that scutellarin intervention reduced protein level of PSTAT3 in LPS-activated BV-2 microglia,enhanced protein level of IL-10.There was no statistical difference in protein level of STAT3 in each group.Conclusions Scutellarin promotes the polarization of BV-2 microglia to M2 type by inhibiting the activation of STAT3,which may be related to the effect of scutellarin in reducing neuro-inflammatory responses.